Locking device for electric switches



Dec. 1, 1925- 1,564,022

R. M. ROBINSON LOCKING DEVICE FOR ELECFI'RC SWITCHES Filed Sept. 28, 1921 ATTORNEY Patented Dec. l, 1925.

UNITE-.D STATES PATENT UFFICI;-

ROBERT Rhninsorn rionrsvriirn, 'Referentin Asseiron To cfrnAtrrAM nLls'C- TRIC sWITCnrN'e nnvron V'0o. INC., or iconsvrrrn, KENTUCKY, A CORPORATION or KENTUCK-tr.

`Lookin@ nnvr'on ron n'nnofrnro SWITCHES.

To all, whom t mag/concern z' i Be it known that I, ROBERT M. RorNsoN, ac tizen of the lUnited States, and aresident of Louisville, county of efferson, `and State of Kentucky, have invented a new and use ul Improvement in` Locking; Devices for Electric Switches', of which `the following is a. specification.,

The object of my invention is to provide a locking device for electric switches of .the Cheatham type shown in Patent No. 612,702 and subsequent patents, so that will be impossible to derail a car by having a switch thrown one way by an approaching car and the other way by a. following car before the Yfirst car is clearot the switch, and a further object is to provide` a `reliable apparatus which will operate properly `without regard to the speed ot' lthe cars using the switch.

These and other objectsare accomplished by niy invention, o ne embodiment of which is hereinafter more particularly set forth.

For a moreparticular descriptionpf my invention, reference is tobe `.had to the accompanying drawings, `forming a part hereoi',in which# l Figure 1 is -adiagrammatie view of a comrletesystem embodying my inrenten .are

Figure -2 is aside eleva-tion of thel'oclnng device. A

Through the various viewsoi the drawings, vsimilar reference characters designate similar parts. if

' inthe embodiment o tmy invention herein illustrated, `a switching system ot the Cheatham type is shown in which r`1 designates the trolley wire, 2 the conventional trolley pan', or any lother trolley pan, the controlling solenoidor relay, l and 5 the 40 'ground solenoi'ds, 6 the movalolel core of the `ground l.solenoids and 7 gthe switch point rail. The trolley pan 2 has a long bar 8 at one side which is `cfmnectedby a wire 9 .to the magnet ot' the relay 3 and from thence a wire 1() runs to the trolley wire 1. The. armature 11 or' the relay 3 has a 'Contact plate 1 2 fixed thereon and this contact plate is connected to a wire 13 which runs to the middle bar 14 ononesi'de of the trolley pan 2. As will ap- `pear below, the wire 13 is interrupted between the contactsd which are connected together when the device Voperates in a manner which will be described below.y The contact plate 12 normally rests on a iixed contact 16 which connected to a wire 17 that runs to the solenoid l which is grounded through a wire 18. lfithe magnet loe-energized suiliciently to raise the core 11, and its .-g

connected parts, the plate 12 contacts With an upper fixed Contact 19 which is connected by a wire l2O to the magnet 5 of the` ground solenoid which solenoid is grounded through a'suitable wire 21 in the conventional nianner. The core 6 is connected to the switch point rail 7 ineans of any suitablemechanisrn 22 which forms no part or my invention.

Assumingzthat the contacts 15 and 1G are connected, the operationof the device, as above described, is the ordinary operation ol 'a lCheatham system, that is, 'assuming a trolley wheel to bridge between the contactors 8 and 14 and to be offithe trolley wire i.

1, the bar 8 is connected to the trolley wire yl through the wires 9 and l0. If no power be applied to the motors of the car connected tothe trolley wheel, the magnet of the relay 1s not suiiiciently energized, if it is ener gized at all, to raise the Core 11 and'so a circuit is established through the lwire 13, contact 16, ground 'solenoid 4t ah'dwir'e 18,'s`o that the switch point 7 Visfplaced for sending checar straight ahead. It .power be `'taken to the 'motors of the car, then enough 'electricity passes through the lI'nagn'et 3 to e'ne'rgize the same suiiiciently toraisethe core 11 and then the plate 12 contacts `v`vith the liked conta-ct 19 andthe ground solenoid 5 is then energizedto throw the switch forthe curve. At times the apparatus above described will operate where one car follows another too closely so that derail'ments or other troubles result when theftollowing car is going inthe opposite direction from the leading car tand `'the switch point'is thrown when the leading car yis partiallythrough theswitch. To prevent this difficulty, my locking device is ein Dloyed. This locking device has a wire 23 which has one 'end connected to a ba'r 24 on the trolley pan which follows the bar 121 'so that the trolley wheel will first connect the bars S and 14;l and then the bars 8 and 24 as indicated in Figure 1. The bars 14: 'and 24 are remote enough to have the trolley wheel leave the former before reaching the later. The wire 23 runs to .a resistance 25 and intermediate of the ends of the same so that there is a comparatively low resistance between the wire 23 and the wire 27. The resistance of the resistance coil 25 may be in the neighborhood of 1400 ohms and the resistance of the magnet 28 may be in the neighborhood of 410 ohms, although this resistance may be varied, if desired. The wire 26 runs to a solenoid 28 which has a wire 29 which connects it to the ground. This solenoid has a core 30 which is insulated on its lower exterior surface, except at the ring 31 which is shown connecting the contacts 15. This ring 31 may connect the lower contacts 15 or the upper contacts 32 depending on whether or not the solenoid 28 is energized. The connections of the contacts 15 have been described above and the contacts 32 connect the wire 27 with a wire 33 that runs to the fixed arm 34 of a trolley wire switch or circuit opener 35.

This trolley wire switch 35 has a base 36 which is fixed on the trolley wire 1 in any desirable manner, and it supports a bar 37 which is fixed thereon and held by screws 38 or by any other suitable means. At its forward end, the bar 37 is provided with a pivot 39 on which is placed a bent contacting .device 40 which has its lower end normally resting on the trolley wire 1 and its upper end in contact with the bar 34. Whenever a trolley wheel `raises the` lower end of the pivoted contact 40, the upper end is separated from the contact 34 so that the circuit is opened at this point. This contact 34 is insulated from the bar 37 by a suitable insulator 41 so that when the contact 40 is raised, as above described, the fixed contact 34 is not energized.

-In view of the foregoing. the operation of my improved locking device will be readily understood. Assuming lthat a trolley wheel passes through the trolley pan in the direction indicated by the arrow in lFigure 1 and the switch point is thrown one` way or another, or not thrown according to the exigencies of the situation, this trolley wheel will pass from the bar 14 to the'bar 24 and when it connects the bars 24 and 8 the magnet 28 will be energized. In any event, as soon as the magnet 28 is energized the band 3lk is drawn away from the contacts 15 and placed in contact with the contacts 32 and then the circuit is opened through the wire 13 so as to prevent any current flowing through either of the ground solenoids 4 or 5 with the result `that before the trolleyl wheel leaves the trolley pan and immediately after it leaves the bar 14 the circuits through the ground solenoids are opened and the switch point rail remains at the place where it belongs. As the trolley wheel proceeds along the trolly wire 1 and before it reaches the releasing device 35 a current will i'iow throughthe contact 4() which .rests on the trolley wire 1, the fixed contact 34,

the wire 33, ring 31,.contacts 32, wire 27 ,7'

resistance 25, wire 26, solenoid 28 and wire 29 yto the ground. As the combined resistance-coil 25 and solenoid 28 aggregate something like 1800 ohms the current flow will be small, say one-quarter to one-third of an ampere, the energy used while the trolley wheel is passing from the trolley pan 2 to the circuit opener 35 is very small. As soon as the trolley wheel strikes the movable contact 40 of this circuit opener 35, the circuit is opened and then the current to the solenoid 28 is cut off and immediately thereafter the core 31 falls and opens the circuit through the contacts 32 and closes the circuit through the contacts 15 so that the switching apparatus is ready for ani other use. The circuit opener ,35 is placed with regard to the switch point rail 7 so that a car will be over the switch point rail and free of the same before the trolley wheel of the car acts on the movable contact 40, as above described.l

In the'preferred embodiment of my invention, the lsolenoid 28 and the core 30 are so arranged and proportioned that the core is drawn up within a very small fraction of a second after the solenoid 28 is energized and yet the weight of the core 30 is suficient to make the ring 31 on this core open the circuit between the contacts 32 immediately upon the deeenergizing of the solenoid 28 so that a car may pass through the apparatus as fast as a car can pass without danger of derailment under the normal conditions of service and without being delayed in any manner so as to give the apparatus time to act, as above stated.

While I have shown and described one embodiment of my invention, it is obvious that it is not restricted thereto, but that it is broad enough to cover all structures that come within the scope of the annexed claims.

I-Iavingthus described my invention, what I claim is: l

, 1. In an apparatus of the class described, an electrically operated switch throwing device with circuits therefor, a solenoid with means connected therewith for opening the switch throwing circuits contained in said switch throwing device and means for closing a circuit through the solenoid for holding open the switch throwing circuits and a circuit opener with a part adapted to be moved by a trolley wheel to open the circuit through said solenoid.

2. In an apparatus of the class described,

`the combination with an electrically operrelay and conn-ections between seid electric switch opening and closing device and said trolley pan and said circuit opening device.

3. In en appztratusloiE the class described, a trolley wire with zt trolley pan and a circuit opener mounted thereon, a switch throwing device connected to said trolley pan, a circuit opener in circuit with said switching device, a grounded solenoid controlling said circuit open-er, connections between said solenoid and the trolley pan and the solenoid and the circuit opener on the trolley wire and suitable resistances in both of said last mentioned circuits so that when the solenoid is energized the circuitr will be opened through the switching device and another circuit closed from the circuit opener on the trolley Wire and through the solenoid and resistance, whereby the first circuit will be openthrough the switching device by a reduced current through the grounded circuit of the solenoid until this circuit is opened through the circuit opener of the trolley wire.

ROBT. M. ROBINSON. 

